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Relationship of Sediment Redox Conditions to Methyl Mercury in Surface Sediment of Louisiana Lakes

R D DeLaune, A Jugsujinda, I Devai, W H Patrick Jr

J Environ Sci Health A Tox Hazard Subst Environ Eng. 2004;39(8):1925-33.

PMID: 15332659

Abstract:

Surface sediment from three Louisiana Lakes containing overlying water layer spiked with 2 microg/g (2 ppm) mercury were incubated under oxygenated (air) and nonoxygenated (N2) conditions for determining the impact of oxygen status of overlying water on methylation of Hg in surface sediment from these lakes. The added mercury resulted in a greater than ten fold increase in methyl mercury (MeHg) as compared to native concentration of MeHg. The increase in methyl Hg production was less in sediment in which overlying water was exposed to oxygen rather than nitrogen. Results suggest that methyl Hg production would be less in lakes containing an oxygenated water column. In parallel microcosm studies without added mercury. MeHg decreased in sediment when redox potential of sediment suspension was increased from -200mV to +50mV. Results of these studies demonstrate the importance of oxygenation or redox condition of surface sediment on mercury methylation and demethylation. Sediment conditions, which either reduce methylation or enhance demethylation in surface sediment, will limit the bioavailability of MeHg to the aquatic environment.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AS2121231 Methyl Mercury in Sediment Methyl Mercury in Sediment Price
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